Preheat oven to 350 F.

Line 13x9” pan with foil leaving one-inch overhanging on two opposite sides.

In a medium bowl, stir together cake mix and pecans.

With a pastry blender or fork, cut in butter until mixture is crumbly.

Lightly press in bottom of foil-lined pan.

Bake 15 to 20 minutes or until set and just beginning to brown. Let cool completely.

In large bowl, fold sherbet into ice cream just until partially blended for marbled design. Spoon and spread over cooled crust.

Cover; freeze until firm, at least 4 hours.

Using foil handles, remove dessert from pan to cutting board 10 minutes before serving. Peel back foil and cut into 15 pieces.

Top each piece with Cool Whip and sprinkle with pecans.